Treatment and assembly of lapped metal parts



Nov. 19, 1940. M. J. ZIMMER 2,222,339-

TREATMEN'I AND ASSEMBLY. OF LAPPED METAL PARTS Filed Oct. 6, 1938 2 Sheet-Sheet 1 INVENTOR. Myron Jlimmer ATTORNEY.

Nov. 19, 1940. M. J. ZIMMER 2,222,339

TREATMENT AND ASSEMBLY OF LAPPED METAL PARTS Filed 0012. 6, 1938 2 Sheets-Sheet 2 INVENTOR.

Myron dl mmer ATTORNEY.

Patented Nov. 19, 1940 UNITED STATES PATENT OFFICE TREATMENT AND ASSEMBLY OF LAPPED METAL PARTS corporation of Illinois Application October 6, 1938, Serial No. 233,626

1 Claim.

This invention relates to the treatment and assembly of lapped metal parts and more particularly frames embodying lapped metal strips such as those of which certain types of can openers, egg beaters and like structures are made.

In certain forms of can opener, for example, the frame consists of a strip of metal folded intermediate its ends to provide a pair of spaced handle arms, the forward portion of said arms 0 being brought together to dispose the inner faces thereof in intimate contact with the opposed sides of a flat cutting element or blade. The blade is secured to the arms by means of rivets which are passed through perforations in the 15 arms of the frame and the blade, or by welding. The usual practice is to plate the frame prior tov the attachment of the blade thereto. The rupturing of the pro-plated coating on the arms incident to the riveting operation, leaves raw metal edges in the material of the frame thereby causing early corrosion of the article. In the absence of rivet heads on the arms, such as is usually the case when the parts are welded toether in lieu of using a riveted connection, the faces of the arm portions adjacent to said connection are left generally plain, smooth and uninterrupted. The plated and polished finish of the arms thus tends to emphasize blemishes in the metal and discoloration, if any, incident to the heat applied thereto in the welding operation.

A welded connection without the presence of projections of rivet-like appearance, furthermore does not present the sturdy-appearing quality of a rivet-fastened structure when viewed on a sales counter.

The present invention contemplates a structure embodying a frame of lapped metal parts or strips, which may be treated prior to the 40 plating operation to provide a design or pattern on the ultimately exposed faces of the fastening area, which will produce outward projections in said surface. By forming projections which simulate rivet heads, a riveted appearance is ch- 45 tained without rupturing the metal and the consequent exposure of raw metal edges therein incident to the use of a riveted connection is eliminated. Under these conditions, the lapped metal parts may be fastened together by welding 50 or the like and yet retain the appearance of a riveted connection.

The present invention also contemplates the formation of depressions in the ultimately exposed faces of the fastening area corresponding 55 to the periphery of the projections aforesaid,

which depressions create projections on the contiguous inner faces of the metal parts through which a welded connection may be established.

t is accordingly an object of this invention to utilize a treatment and assembly of struco tures embodying lapped metal parts which will not only simplify the production of articles of this nature but will provide a product of improved construction and appearance.

With the above and other objects in view, as 10 will be apparent, this invention consists in the construction, combination and arrangement of parts all as hereinafter more fully described, claimed and illustrated in the drawings, wherein:

Fig. l is a plan view of a can opener having a frame construction embodying lapped metal parts treated and assembled in accordance with this invention.

Fig. 2 is a side elevational view thereof.

Fig. 3 is an enlarged fragmentary view of the fastening area, to show details of the method contemplated by this invention.

Fig. 4 is a transverse horizontal section taken on line 44 of Fig. 3 with the parts disassembled.

Figs. 5, 6 and 7 illustrate an egg beater comprising a frame of lapped metal parts utilizing a slightly modified form of treatment and assembly in keeping with the present invention.

Reference being had more particularly to the drawings, the numerals l0 and H designate the spaced handle arms of a can opener having a loop-shaped handle formed of a strip of metal rebent intermediate its ends. An end portion l3 of the arm I I is bent to overlie a forward portion H of the arm II, the leading edge portion of the part [3 being disposed in proximity to the leading edge of the portion l2 of the arm ID. The portions l2, l3 and M are preferably brought together to receive and retain a cutting blade 15 therebetween. It is to be understood that the formation of the metal strip with the inwardly bent lapped portions l2, l3 and I4 does not necessarily require that the arms ID and Il consist of a single unitary piece. This strip may be of one or more pieces and the end portion 13 of the arm ll may be formed from the arm ii] if desired.

According to the teaching of this invention, the portions l2, l3 and M are provided with outwardly projecting bosses or prominences I6 formed by stamping or the like. The bosses I6 may be of any desired shape and contour, being preferably aligned transversely of the arms [0 and II and of uniformly semi-spherical contour to simulate the heads of rivets. After this has been accomplished, the frame is in condition for plating, if desired, or any other desired treatment prior to attachment of the cutting blade. Thus the surfaces of the portions I2, I 3 and M are not only finished to obscure blemishes, if any, in the metal of the frame but are treated to give the appearance of a riveted connection without necessitating rupture of the metal and exposure of raw metal edges to cause early corrosion which would follow as in the case of actual riveting methods.

By providing a plurality of welding projections extending outwardly from both faces of the blade l and toward the inner faces of the portions I2, l3 and M, as shown in Figs. 3 and 4, and passing a welding current through oppositely disposed electrodes against the outer faces of the portions l2, I3 and I4 while the projections I! of the blade |5 are firmly pressed between the inner faces of said portions |2, l3 and M, a Welded connection may be established between the parts.

Figs. 5, 6 and '7 illustrate an egg beater handle frame consisting of lapped metal parts, utilizing a slightly modified form of treatment and assembly contemplated by this invention. In the article as shown on the drawings, the frame comprises a pair of fiat strips of metal 23 and 2| having portions 22 and 23 respectively brought together to form a fastening area. Corresponding end portions 24 and 25 of the strips 20 and 2|, respectively are turned outwardly to form parallel legs between which a handle member 26 may be supported, and corresponding end portions 21 and 28 of the strips 20 and 2|, respectively, are bent to provide spaced legs for supporting a driving gear 29 therebetween.

In carrying out the form of frame construction shown in Figs. 4, 5 and 6, the portions 22 and 23 are each provided with outwardly projecting bosses or prominences 30 formed by stamping or the like. These bosses 30, like the bosses l6 shown in Figs. 1, 2, 3 and 4, may be of any desired shape and contour, being preferably aligned transversely of the strips 20 and 2| and of uniformly semi-spherical contour to simulate the appearance of rivet heads. Instead of using spaced welding projections on the inner faces of the portions 22 and 23, such as the projections extending outwardly from both faces of the blade l5 as shown in Figs. 3 and 4, the area of the portions 22 and 23 surrounding the bosses 3|] is provided with a shallow indentation or groove 3| concentrically positioned with respect to the adjoining boss 30. This indentation 3| is sufllciently wide and deep as to create a ring-like projection 32 on the inner face of each of the portions 22 and 23. Thus a welded connection may be established between the portions 22 and 23 by passing a welding current through oppositely disposed electrodes applied to the outer faces of the portions 22 and 23, while the projections 32 of each strip are in juxtaposition.

While a can opener and an egg beater handle frame have been shown and described to represent certain embodiments of the present invention, it will be understood that articles of widely varied construction consisting of lapped strip metal parts secured to form a unitary frame, may be made without departing from the scope of this invention, as set forth and defined in the following claim:

What is claimed:

The treatment and assembly of an article embodying two or more lapped pieces of metal stock secured together as a unit comprising providing the ultimately exposed faces of said pieces with aligned outwardly projecting bosses, indenting the surface of said pieces surrounding said bosses to form a projection on the inwardly directed faces of said pieces, arranging said projections in juxtaposed relation, and rigidly connecting said pieces by means of a Welding current passed through said projections.

MYRON J. ZIMMER. 

